How To Clean Laboratory Instruments And Equipment?

Glassware commonly used in laboratories, such as measuring cups, test tubes, burets, pipettes, measuring bottles, etc. The equipment will be stained with oil stain, scale, rust stain, etc. in the process of use. If it is not cleaned completely in time after use, it will lead to deviation of results, and even have a very bad impact on the service life and performance of the equipment. Therefore, the glassware used in chemical experiment operation must be clean and tidy.
1、 Washing methods for some glassware:
(1) Wash with water
According to the shape of the glassware to be cleaned, choose your own brush, such as tube brush, measuring cup brush, flat brush, buret brush, etc. Brushing with a brush dipped in water can dissolve the soluble substances, or the dust and insoluble substances stuck to the glassware can fall off, but oil stains and organic substances cannot be removed in many cases.
(2) Wash with detergent
The inner and outer walls of glassware can be carefully brushed with a brush. In order to ensure the cleaning efficiency, the detergent can be mixed into 1%~5% aqueous solution and heated to soak the glassware to be washed. After a few minutes, continue to use the brush repeatedly.
(3) Clean with a special ultrasonic cleaner for laboratory instruments. The special ultrasonic cleaning machine for the laboratory is based on the principle of efficient ultrasonic cavitation effect. Water molecules vibrate in glassware and shake off pollutants on the surface of equipment. Under the influence of the ultrasonic cleaning machine, it can quickly clean dead corners and gaps, replacing places that cannot be cleaned by traditional manual cleaning. Finally, the equipment can be used again after being dried.
2、 Select detergent
Generally, commercially available synthetic detergents can be used to clean glassware. When the inner wall of the equipment is attached with insoluble substances and cannot be cleaned with synthetic detergents, appropriate detergents should be selected according to the nature of the adhesive. If the adhesive is alkaline, dilute hydrochloric acid or dilute sulfuric acid can be used to make the adhesive react and dissolve; If the adhesive is alkaline, sodium hydroxide solution can be selected to make the adhesive react and melt; If the adherent is difficult to dissolve in acid or alkali, but easy to dissolve in some organic solvents, such organic solvents shall be used as detergents to dissolve the adherent
In the laboratory, as well as the specially prepared cleaning solution, it can be recycled several times
The following cleaning solutions can be configured for chemical cleaning of many utensils that are inconvenient to be cleaned with a brush. After cleaning, the utensils used to analyze some trace metals should also be immersed in hydrochloric acid, nitric acid solution or solution containing complexing agent of specific concentration for a long time to remove the heavy metal ions adsorbed on the surface, and then be cleaned with distilled water.
3、 Master the operation steps of cleaning glass instruments
For simple instruments and equipment with easily removable substances, such as test tubes and beakers, use a test tube brush dipped in synthetic detergent for cleaning. When rotating or moving the test tube brush up and down, use proper force to avoid damaging instruments and equipment and scratching the skin
Some glass instruments with fine and complicated structures cannot be cleaned with a brush, such as measuring bottles and pipettes, but can be soaked with cleaning solution
The cleaning operation is introduced as follows: At the beginning of cleaning, check whether the rubber plate on the piston is fastened to avoid slipping and damage during cleaning; Pay special attention to whether there is water leakage and blockage, if any, adjust it. Close the piston, inject 2~3ml of cleaning solution into the buret, slowly tilt the buret to the horizontal, slowly rotate the buret, so that the inner wall is immersed in the cleaning solution. Erect the buret, unscrew the piston, and discharge the cleaning solution, so that the section of the piston can also be washed. Then wash it with daily tap water, and discharge it from the tip at the lower part of the piston, Do not pour out the liquid from the upper nozzle to save time and effort
4、 Clean the glassware immediately
Cleaning the glass instrument immediately is beneficial to selecting the appropriate detergent. After all, it is easy to determine the nature of the residue at that time. There are some chemical experimental operations, in which the residual liquid after reaction is poured out immediately. There are no hard to remove attachments left on the inner wall of the instrument and equipment. However, after being placed for a period of time, the volatile solvent escapes, and the residue will adhere to the inner wall of the instrument and equipment, making cleaning difficult. There are many substances that can react with the instrument itself, If not cleaned in time, instruments and equipment will be damaged or even destroyed.
5、 Other common precautions
Do not mix all kinds of experimental reagents to be used as detergents, and do not use all kinds of experimental reagents to clean glass instruments at will. This not only wastes drugs, but also is very dangerous